CN1344410A - Device for writing information onto information carrier - Google Patents

Abstract

A device according to the invention for writing information to an information carrier (1) includes conversion means (7) for converting symbols in an information signal (SINFO) into pulse sequences in a control signal (STR). The device further includes a transducer (10) for generating a physically detectable pattern on the information carrier (1) in response to the control signal (STR). The conversion means (7) include assignment means (702) for assigning properties of the pulse sequences to symbols in the information signal (SINFO). These properties include the duration and the magnitude of pulses in the pulse sequence. The conversion means (7) further include at least one counter (711) for supplying a count signal (TC1) after a time interval, which counter is coupled to the assignment means (702). The conversion means (7) further include a controllable delay line (761) coupled to the at least one counter (711), for delaying the count signal (TC1), and to the assignment means (702).

Description

Be used for equipment with information writing information carrier

The present invention relates to equipment with information writing information carrier.

According to USP5,126,985, known a kind of pyromagnetic type be used for equipment with information writing information carrier.This known device has a transducer to be used for producing the detectable pattern of physics on information carrier.This transducer comprises an optical writing head and a magnetic write head.This equipment comprises that it is that optical writing head and magnetic write head obtain control signal that a synchronizing circuit is used for according to information signal.Synchronizing circuit comprises a phaselocked loop, and this phaselocked loop obtains clock signal from information signal, and this equipment also comprises a time-delay element, and this element provides delay clock signal as write signal.When the writing rate of higher information density of needs and Geng Gao, be necessary to control more accurately the variation length that instantaneous and write signal take place.By improving circuit by synchronous clock frequency, the accuracy of these parameters can get raising to a certain degree.Yet the maximum clock frequency of permission is limited.

A target of the present invention is further to improve the precision of described parameter, and need not improve clock frequency.For this reason, the present invention provides a kind of equipment that is used for to the information carrier writing information, this equipment comprises the conversion equipment that is used for the symbol transition of information signal is become the pulse train in the control signal, this equipment comprises that also a transducer is used for producing the detectable pattern of physics according to control signal on information carrier, wherein conversion equipment comprises the distributor that is used for the attribute assignment of pulse train is given the symbol of information signal, attribute wherein comprises the extended period and the amplitude of pulse in the pulse train, conversion equipment wherein comprises that also at least one counter is used for providing count signal in the time segment in the past, this counter links to each other with distributor, wherein conversion equipment comprises that also the controllable delay line that links to each other with at least one counter is used for the delay counter signal, and this lag line also links to each other with distributor.

In the device in accordance with the invention, conversion equipment with information to be written for example the symbol transition of EFM coded message become to have the pulse train of extended period and amplitude.By counter, can obtain for pulse duration thicker control relatively, this control is subjected to counter can be by the restriction of synchronous maximum clock frequency.Yet controlled lag line makes might come the delay counter signal with a temporal resolution, and this temporal resolution is more accurate than clock signal, has therefore further improved the precision of the pulse parameter that will produce.

With reference to the accompanying drawings, these and other aspect according to the present invention can be clearer.In the accompanying drawings,

Fig. 1 provides according to equipment of the present invention;

Fig. 2 provides the part of this equipment in more detail;

Fig. 2 A provides among Fig. 2 that part of more detailed description among the view IIA;

Fig. 3 provides another part of equipment among Fig. 1;

Fig. 4 provides the content that belongs to the memory storage of part among Fig. 3;

Fig. 5 provides Fig. 3 and provides the example signal that occurs in the part;

Fig. 6 provides the circuit part that provides part among Fig. 3;

Fig. 7 provides the details of circuit part among Fig. 6;

Fig. 8 provides another circuit part of part among Fig. 3.

Fig. 1 provides the equipment that is used for to information carrier 1 writing information.In present case, this equipment has one first operator scheme to be used for to the information carrier writing information, and has second operator scheme and be used for from the information carrier sense information.Information carrier 1 is for example, only to write type one time, as the information carrier of ablator type.Optional in addition, this information carrier can be a rewriting type, and for example, a kind of information carrier with following material information layer: material wherein has the non-type structure, and this structure can be by heating and cooling Information Level continuously and partial transformation becomes crystalline texture.This material for example is, Te, the alloy of Se and Sb.One of this material is presented in G. Bouwhuis, J.Braat, A.Huyser, J.Pasman, G.vanRosmalen and K Schouhamer Immink Admin Hilgerlth, Bristo1 1985, pp 219-255's " Principles of Optical Disc System " in provide.Optional in addition, this information carrier for example can be, light-magnetic type.These information carriers have the Information Level of a magnetisable material.To surpassing Curie temperature, magnetic is affected by this Information Level of spot heating, and way is for example to pass through laser beam, applies a magnetic field simultaneously and realizes.

Assisting down of error correction code device 8, can be to input signal S _INCarry out error correction code.Input signal S _INExpression, for example, video data stream, audio data stream or computer data stream.Then, assisting down of channel coding device 9,, can produce information signal S according to coded signal by chnnel coding _INFOChannel coding device 9 is, for example, and EFM or EFM+ channel coding device.Information signal S _INFOComprise the symbol of representing with alternate form, signal has a constant logical value in described interval.

This equipment comprises a conversion equipment that is formed by control module 7, is used for information signal S _INFOIn symbol transition become control signal S _TRUnder present case, control signal S _TRBe a supplying electric current, be used to radiation source 11 to provide energy as solid-state laser.

Radiation source 11 forms the part of transducers 10, wherein transducer under first operator scheme according to control signal S _TRBut on the Information Level 2 of information carrier 1, produce the pattern of physical detection.

In the current embodiment of this equipment, but transducer 10 also can produce read signal S according to the physical detection pattern on the information carrier in second operator scheme _LSUnder second operator scheme, transducer 10 also receives control signal S from control module 7 _TR, this signal provides electric power for radiation source 11.Under second operator scheme, supplying electric current S _TRIt can be constant.Yet if under this operator scheme, it is just relatively good that supplying electric current is given a high frequency modulated.This modulation has suppressed relative very noisy.

In this embodiment, this equipment is adjusted to reading writing information from the disc-shaped information carrier 1.For this purpose, this equipment has a motor 13 to be used for rotating information carrier 1, and this equipment also has a control module 14 to be used to control motor 13.The radial location of transducer 10 is determined by servo-drive system 15.Servo-drive system 15 and control module 14 are by microprocessor 16 controls.Motor 14, servo-drive system 15 and microprocessor 16 are traditional types.This equipment also comprises the adjustment unit 17 by microprocessor 16 controls.Adjustment unit 17 is from one or more sensor received signal S _FS, S _LS, and adjust the parameter of control module 7 by universal serial bus 18 according to these signals.Like this, what can realize is, radiation source 11 not raying of emitted power sources 11 aging and/or add heat affecting.It also makes the power that imposes on radiation source 11 adapt to the state of information carrier 1, consequently might realize the reliable record of write signal, for example, even under the pointer sign situation on the information carrier, also be like this.

In this embodiment, this equipment has a switch 19.By this switch 19, the user can be arranged to this equipment first operator scheme or second operator scheme.Under second operator scheme, information signal S _INFOValue remain unchanged and enter first operator scheme once more up to this equipment.

In this embodiment, transducer 10 is used on information carrier write information or read message from information carrier.In addition, different transducer can be used for read and write information.Fig. 2 provides transducer 10 in more detail.Except radiation source 11, transducer also comprises a photosystem and one first detecting device 20 and second detecting device 21.Photosystem comprises the first light beam dispenser 22, lens 23, the second light beam dispensers 24, focusing objective len 25 and astigmatic element 26.Second detecting device 21 is divided into sub-detecting device 21a-21d (seeing Fig. 2 A).Under first operator scheme, radiation source 11 is according to control signal S _TRProduce the emission light beam.The sub-fraction that the first light beam dispenser 22 will be launched in the light beam projects to first detecting device 20.The output signal S that first detecting device 20 provides _FSBe applied in to adjusting gear 17 so that the power of supplying with to radiation source 11 is provided according to 11 pairs of power that provided of radiation source.In addition, emission light beam scioptics through light beam dispenser 24 and by focusing objective len imaging on the Information Level 2 of information carrier 1, and produce physics and can detect effect, in this case, are that a kind of light on this layer can detect effect.Under second operator scheme of this equipment, radiation source 11 also produces the emission light beam.Same method in the employing and first operator scheme, the imaging on Information Level 2 of emission light beam.The emission measure that reflects from Information Level 2 can detect effect and difference according to light.Emission after the reflection is by focusing objective len 25, light beam dispenser 24 and astigmatic element 26 imaging on detecting device 21.Corresponding to the emission of incident, detecting device 21 produces a signal, is four times of signals in this case.Pretreater obtains signal FE from these four times of signals, signal RE and read signal S _LSServo-drive system 15 uses signal FE to be used for the emission light beam on the information carrier 1 is carried out focus control.Servo-drive system 15 uses signal RE to be used for the radial location of transducer 10.

Channel decoding device 30 and error correction decoding device 31 are from read signal S _LSObtain output signal S _OUT

Fig. 3 provides transposition device 7 in more detail.Transposition device 7 comprises that device 702 is used for giving information signal S with the attribute assignment of pulse train _INFOSymbol.Distributor can, for example, take the form of microprocessor, it calculates the attribute that will be assigned with by a kind of algorithm.In this embodiment, distributor is formed by memory storage 702, and wherein, for each symbol that will write, a series of message units that relate to the pulse train that will produce are stored.Each message unit comprises one first parameter S EL1, and this parameter is the sign that the width of cloth is penetrated the quiescent current setting in source 11.This message unit also comprises a parameter S EL2, and it is the sign of difference current, offers the total current S of radiation source 11 _TREqual quiescent current and difference current and.Message unit also comprises the first parameter TIM1 and the second parameter TIM2, and which time interval they determine in the electric current S that is provided with by LVL1 and LVL2 _TRBe held.Go over electric current S when this time interval _TRSetting determine by next message unit.Message unit also comprises a parameter MOD, and it determines whether the electric current by radiation source is applied extra modulation.When this equipment in second operator scheme following time, this modulation is good.It has suppressed so-called stronger noise (RIN) relatively.Memory storage 702 is connected to first in first out (FIFO) register 703.Fifo register is by address generator 704 addressings, and this generator is by state machine 705 controls.For this purpose, address generator provides a write address F for fifo register 703 _WWith one read address F _RAddress generator 704 is gone back the output signal of count pick up device 701, and this signal determines to write the time of symbol.State machine 701 also provides one to select signal Cs for demodulation multiplexer 709.

Conversion equipment 7 has one the first pulse control unit A and the second pulse control unit B.Each pulse control unit comprises that all one first and second counter 711,712 is used for providing signal TC when the time interval of first parameter TIM1 definition is expired ₁And TC ₂Each all has one first input " beginning " counter 711,712, and clock input " CL " is used to load the input " loading " of starting value, and this input is represented that by TIM1 they also have an output " TC " to be used to provide count signal TC ₁, TC ₂, when their expressions reach the terminal point of counting region.The loading input of counter 711,712 is linked to memory storage by demodulation multiplexer 709 and fifo register 703.Be activated as long as counter begins input by it, counter begins to count downwards from the value that the loading input loads, and provides signal TC when counting end downwards ₁, TC ₂The clock input of counter receives reference signal CL, and this signal is from information signal S _INFOIn obtain.The output TC of first and second counters is linked to the input that begins of second and first counter.Each counter 711,712 is linked to controllable delay line 761,762 and is used for delay counter signal TC ₁, TC ₂Lag line 761,762 can be expressed the signal controlling of parameter TIM2.Lag line 761,762 passes through corresponding registers 731,732 and is connected to memory storage 702 by demodulation multiplexer 709 and fifo register 703 to be used to store this parameter.Each lag line 761,762 has an output to be attached to the different input ends of OR door 707.OR door 707 has an output to be attached to the triggering input end of DA converter 706.The register 741 that is used for stored parameter LVL1 and LVL2 is corresponding to counter 711.Another register 742 that is used for described parameter is corresponding to counter 712.Register 741,742 is attached to another input end of DA converter 706 by ternary buffer memory 751,752.When OR door 707 receives trigger pip, DA converter 706 offers solid state radiation sources 11 in another input end sampling and with the electric current STR of correspondence.Conversion equipment 7 comprises that also a calibration circuit 770 is used to lag line 761,762 that calibrating signal I is provided.Its advantage is that the delay in the lag line can avoid varying with temperature or avoid the influence of wearing out.In addition, therefore attainable is lag line 761,762 for the set-point of parameter TIM2 basically with same retardation delay counter signal TG ₁, TC ₂

The operation of conversion equipment will be explained with reference to Figure 4 and 5.Fig. 4 provides the example of part memory storage content.Fig. 5 provides some signal waveforms, and they appear in the transposition device among Fig. 3.Decoding device 701 is from information signal S _INFOIn obtain symbol II, the length of the symbol that it indicates to write.Symbol II is corresponding to start address 702, and wherein the first information unit of this symbol is positioned.Fig. 4 provides the memory contents of the symbol of indicating with I6 among the EFM by example.Certain interval of this symbolic representation, wherein, information signal has a constant value that continues 6 clock period.The first information unit that is positioned at reference to the AI6 address is loaded into fifo register, and its address is by the signal F from address generator 704 _WDefinition.Then, message unit is loaded into the counter selected by signal Cs for example 711 from fifo register 703, and is loaded into relevant register 731,741 by demodulation multiplexer 709.The starting value TIM1 that the counter of selecting at instant t 0 711 begins to be subordinated to first information unit counts downwards.During counting downwards, the selection signal Cs supposition logical value " 0 " of state machine 705, consequently, second message unit (address AI6+1) can be loaded into pulse control unit B.When the downward counting of counter 711 when the moment, t1 finished, this counter provides signal TC ₁This signal enabling counter 712, this counter load the starting value TIM1 of second message unit simultaneously.At moment t1 ', lag line 761 provides signal TC ₁', this signal has a length of delay, and this value is by relating to signal TC ₁Register 731 in value TIM2 definition.Corresponding to signal TC ₁', trigger pulse T _RAppear at or door 707 output terminal.At described moment t1 ', the ternary buffer memory 752 of the second pulse control unit B is in out state (PS ₂=" 1 "), consequently the value of register 742 output terminals is sampled by DA converter 706.At moment t1 ' signal S _TRSuppose the value LVL1 of second message unit and value that LVL2 represents in present case for preheating pulse P.In the downward counting process of the counter 712 of pulse control unit B, the 3rd message unit (address AI6+2) is loaded into pulse control unit A.When the downward counting of counter 712 when the moment, t2 finished, this counter provides signal TC ₂, consequently, the counter of the first pulse control unit A is activated.Then, lag line 762 provides signal TC at moment t2 ' ₂', this signal has a length of delay, and this value is by relating to signal TC ₂Register 732 in value TIM2 definition.Corresponding to signal TC ₂', or door 707 provides trigger pulse T _RTherefore, be loaded into simultaneously the value LVL1 of the 3rd message unit in the register 741 and LVL2 at described moment t2 ' by the DA converter sampling, consequently, preheat pulse P and be terminated, write pulse W (LVL1=2, LVL2=5) beginning.Following after the write pulse bias pulse B (LVL1=2, LVL2=2).Similarly, write pulse and bias pulse meeting alternately produce four times continuously, thereafter, can follow cooling pulse (LVL1=2, LVL2=3) and erasing pulse (LVL1=2, LVL2=4).

In this embodiment, conversion equipment has two pulse control unit A, B, and one of them pulse control unit is loaded and another pulse control unit is activated.Very short pulse duration in the control signal if desired, another embodiment of great use, wherein conversion equipment has relatively large pulse control unit, for example 8, wherein a plurality of pulse control units (for example 2) are loaded simultaneously.Like this, have more time load pulses control module.

Fig. 6 has provided one of them lag line 761 in more detail, and another lag line 762 is identical with it.The lag line 761 that provides comprises a series of delay elements 62,63,64 ...The input of lag line and delay element 62,63,64 ... output be connected to each input end of multiplexer 61.Multiplexer 61 also has a control input to be connected to register 731, the value of this register-stored parameter TIM2.By the signal TIM2 of control input end, the input signal TC of lag line ₁Or one of them output signal of delay element 62,63,64 can be selected, therefore makes signal TC ₁Delay can equal Be Controlled in the step of a clock period part of reference clock CL in step-length.Step-length determines that by calibrating signal I in this case, signal I is a bias current.Current mirror 60 offers each delay element 62 with the duplicate of bias current I ...Delay element 62 ... a length of delay is arranged, and this value is shorter, and bias current I is bigger.Because the delay element of lag line 761,762 receives the bias current I that equates, thereby for the set-point of parameter TIM2, they produce identical length of delay.

Fig. 7 provides a delay element 62 of lag line 761 in more detail.Other delay element is identical with it.These delay elements comprise first and second reversers 621,622.Each reverser has an input 625,626, one first supply line 627,628 of 623,624 a, output and second supply line 629,630.The input 623 of first reverser 621 forms the input of delay element 62.The output 625 of first reverser 621 links to each other with the input 624 of second reverser 622.The output of second reverser 622 forms the output of delay element 62.First supply line 627 of first converter 621 and second supply line 629 receive from the supplying electric current I in the first current supply source 631 with from the identical but opposite polarity supplying electric current I of the amplitude of earial drainage current source 60.The supply line 628,630 of second converter 622 by voltage source V+, V-provides energy.Supplying electric current I equals bias current and serves as calibrating signal.Current mirror 60 also forms delay element 63 in the lag line 62 ... the earial drainage source.

Signal TC when delay element input end 623 places ₁During change, the value at output 625 places of first reverser 621 also changes, but has a time constant that is inversely proportional to bias current I.Compare with first converter 621, second reverser 622 does not produce any suitable delay because, it can from voltage source V+, V-draws bigger basically electric current.Second reverser 622 compensates the reverse of first reverser 621, consequently flows into signal TC ₁Only be delayed.

Fig. 8 provides calibration circuit 770.Calibration circuit 770 comprises phase comparison device 71, the loop filter 72 of low-pass filter form, lag line 74.Lag line has delay element 77,78,79, and they are identical with the delay element of describing with reference to figure 7 62.Lag line 74 has an input end and an output terminal to be connected to each other by retrodirective component 76.Lag line 74 is operated as ring oscillator.The electric current I that current mirror 75 leakage current mirror images 70 provide.This current mirror 70 is driven by earial drainage current source 73, and this current source is by the output control of loop filter 72.Ring oscillator 74,76 has an output terminal to link to each other with the input end of phase comparison device 71.Phase comparison device 71 also has an input end to link to each other with reference signal CL.Delay element 77 ... in delay, therefore, the frequency that ring oscillator 74,76 produces depends on bias current I.Phase comparison device 71, loop filter 72, controllable current source 73, current mirror 70, the ring that ring oscillator 74,76 forms be as phase-locked loop operation, and consequently ring oscillator is with identical frequency oscillation, and has identical phase place with reference signal CL basically.This means that for electric current I each delay element 77,78 is setovered in the following manner, promptly produce the delay τ that equals T/2N, wherein T is a lasting cycle of reference signal, and N is the delay element number in the lag line 74.In this case, lag line 74 has 5 delay elements, and delay τ is 0.1T.Best is that lag line 761 and 762 has the delay element of the lag line 74 that doubles calibration circuit 770.This makes to come the signal TC in the lag line 761,762 with time interval n τ ₁, TC ₂Postpone, wherein time interval value n τ can change in the scope of 0～T.It is also noted that what replace phase comparison device 71 is that the frequency comparison means can be used.

Although described the present invention with reference to preferred embodiment, the present invention is not limited.Therefore, under the situation that does not depart from the scope of the invention that defines in the claim, for a person skilled in the art, a lot of variations can be arranged.The present invention as embodying, can realize that different " method " can be realized by same hardware by hardware and software mode in this equipment.The element outside the element of mentioning in the claim is not got rid of in the use that term " comprises ".Indefinite article before the element " a " do not get rid of the appearance of a plurality of this elements, the present invention exists and any new feature or a plurality of combination of features.

Claims (6)

1. be used for the equipment to information carrier (1) writing information, this equipment comprises that conversion equipment (7) is used for information signal (S _INFO) in symbol transition become control signal (S _TR) in pulse train, this equipment comprises that also a transducer (10) is used for according to control signal (S _TR) at information carrier (1) but go up to produce the physical detection pattern, this conversion equipment (7) comprises that distributor (702) is used for giving information signal (S with the attribute assignment of pulse train _INFO) in symbol, this attribute comprises the extended period and the amplitude of pulse in the pulse train, this conversion equipment (7) also comprises at least one counter (711), be used at a time between section provide count signal (TC after exceeding the time limit ₁), this counter (711) is connected to distributor (702), and wherein conversion equipment (7) comprises that also a controllable delay line (761) is connected with at least one counter (711), is used for delay counter signal (TC), and is connected to distributor (702).

2. the equipment in the claim 1 is characterized in that distributor (702) is formed by memory storage.

3. the equipment in the claim 2 is characterized in that lag line (761) comprises a series of delay elements (62,63,64) and a multiplexer (61), and this multiplexer (61) has some signal inputs, and they are attached to the corresponding output end of delay element separately.

4. the equipment in the claim 3, it is characterized in that comparison means (7) also comprises a calibration circuit (770), this circuit comprises a ring oscillator (74,76), this oscillator comprises a series of delay elements (77,78,79), the delay element of delay line (761) and ring oscillator chain (74) has a length of delay, this value is controlled by calibrating signal (I), calibration circuit also comprises error signal generation device (71), is used for producing error signal according to the output signal and the reference signal (CL) of ring oscillator, and comprises the device (72) that is used for producing according to error signal calibrating signal.

5. the equipment in the claim 4 is characterised in that the lag line (762) that conversion equipment (7) comprises one or more counters (712) and is attached thereto, and each lag line (761,762) is controlled by calibrating signal (I).

6. the equipment in the claim 4, be characterised in that delay element (62) comprises first and second reversers (621,622), each reverser has an input (623,624), output (625,626), first supply line (627,628) and second supply line (629,630), the input (623) of first reverser (621) forms the input of delay element (62), and the output (625) of first reverser (621) links to each other with the input (624) of second reverser (622), and the output (626) of second reverser (622) forms the output of delay element, first supply line (627) of first reverser (621) and second supply line (629) receive respectively from the supply power in the first current supply source (631) and etc. amplitude, the supplying electric current from earial drainage source (60) of anti-polarity circuit, the supply line (628,630) of second reverser (622) is by voltage source (V+, V-) provide energy, supplying electric current (I) serves as calibrating signal.

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